It has to be the 60s. Bob Dylan (can't sing but he sure can write), Joan Baez, Peter Paul and Mary, John Denver (was a member of the Chad Mitchell Trio) Judy Collins,
Simon and Garfunkel, Neil Diamond, Lovin's Spoonful, Mammas and Pappas, Carley Simon, Elton John, and the list goes on and on. Some of these became more popular in the 70s but they started in the 60s.
The reason this decade was so important is that because of the issues surrounding the Vietnam War, Civil Rights and other issues, the music began to talked more about the Saturday Night Dance or Leader of the Pack. These songs carried incredible messages that are still relevant today.